The opposition has warned that the election is "only 37 question times away" and spent the weekend setting out the issues it wants to talk about: the GST, health, education and unease within the Coalition.

Amanda Vanstone called on Mr Abbott and other long-serving Liberal MPs such as Bronwyn Bishop and Philip Ruddock to resign. Photo: David Mariuz

"You don't get very far into the alphabet before you get chaos."

Parliament resumes on Tuesday after a summer in which there has been no shortage of political news such as the resignations of ministers Mal Brough and Jamie Briggs from the frontbench as well as tension within the Coalition about what should happen after the plebiscite on marriage equality.

"Unless I have been lied to, and that can happen, Abbott has told a number of people that he is young enough to have another crack at the leadership. Even if that is meant in the most pure and innocent form, as in, "Well, the Prime Minister might be hit by a proverbial bus", it does not augur well for the future," Ms Vanstone wrote in a piece for Fairfax Media published on Sunday.

"It shows an incapacity on Abbott's part to see what went wrong and how much of that related to his own behaviour. It also reveals a failure to recognise that there are others who have come up in the ranks and will continue to so do."

Ms Vanstone called on Mr Abbott and other long-serving Liberal MPs such as Bronwyn Bishop and Philip Ruddock to resign.

"Political teams are like rose bushes – you have to keep pruning or there are no new blooms ... Pruning delivers results. Bronwyn Bishop, Philip Ruddock and a few others should stop being so selfish, start showing a bit of gratitude for all they have enjoyed, and allow some new blooms to burst forth."

It wants the legislation passed by the Senate by March and is prepared to attach a sunset clause to win over wavering crossbenchers.

The legislation has already been knocked back twice. If it is rejected again it would give the government a trigger for a double-dissolution election.

Prime Minister Malcolm Turnbull said last week that an election was likely to be held some time in August, September or October. This gives the government time to sell the May budget as well as a tax package.